Edge finishing shoe outer bottoms



July 18, 1967 c. ISAACSON 3,331,147

EDGE FINISHING SHOE OUTER BOTTOMS Filed July 25, 1964 1] 106 [08 705 3J04 516 10825 1 d 1 6 105 11.2 7/5 5 z- W1 A 1/0 Inventor CalvinZsaacson By his flfzorney United States Patent 3,331,147 EDGE FINISHINGSHOE OUTER BOTTOMS Calvin Isaacson, Wellesley, Mass., assignor to UnitedShoe Machinery Corporation, Flemington, N..I., a corporation of NewJersey Filed July 23, 1964, Ser. No. 384,726 Claims. (Cl. 36--25)ABSTRACT OF THE DISCLOSURE The invention is directed to edge finishedshoe outer bottoms, and a method for producing them. In finished formthe edges of the bottoms are trimmed and support a sizing and a coatingincluding a polyurethane composition.

The present invention relates to edge finishing shoe outer bottoms, andmore specifically shoe outer bottoms which are fibrous in nature.

When used in this paper the terminology shoe outer bottom has referenceto an outsole, sole, heel, welt, lift, platform and similar other parts,whose edges or edge surfaces are exposed in a finished shoe or otherfootwear. Of these parts, outsoles are the most prominently involved andaccordingly they will be most often referred to throughout. In referringto the shoe outer bottom as fibrous or fibrous in nature it is intendedthat there be included those of leather and various composite materialsin which fibrous fillers are bonded by various resins, adhesives and thelike.

Edge finishing of shoe outer bottoms, for instance an outsole, may becarried out prior to or after the incorporation into a shoe assembly ora finished shoe.

Edge finishing generally includes the basic operations of edge trimmingand edge coating. Edge trimming involves contouring or shaping theoutsole, etc. in outline by use of cutting tools, such as knives, etc.Edge coating then involves the application of a coating(s) which mayalso be referred to as a finish(es), to the edge surface exposed orotherwise provided as a result of edge trimming. Edge trimming may besingle or multi-step in nature. For instance, a first cutting step, orrough rounding may be carried out to be followed by a second, or later,smooth rounding, and, as well an abrading step or steps may be used.Edge coating may also be single or multi-step in nature, and, generallyis the latter. Decorative or protective edge coatings may be applied ina single pass, or in a number of passes. In addition, drying, curing,setting and similar other steps such as burnishing and the like may alsobe practiced as part of the edge coating operation.

In the case of shoe outer bottoms, which are of a fibrous nature, forinstance leather, finished edges obtained from following conventionaledge finishing procedures, have been the subject of continuingcomplaints. The most frequent complaint is that the finish coatings,generally waxes, lacquers, varnishes, mixtures of the preceding, etc.,lack sufiicient adherence to or adhesion with shoe outer bottom edgesurfaces to which they are applied. The coatings crack away or are Wornofi all too easily with normal shoe wearing. In this regard it should benoted that normal wearing is actually quite a severe test. It involvescontinued flexing of the shoe, and as well the shoe bottom, accompaniedoften with exposure to dampness, saline and other stringentenvironmental conditions.

Lack of sufiicient adherence between edge coatings and shoe outer bottomedge surfaces, which is obtained by conventional practices, is in manyinstances due to failure to obtain a cleanly cut edge surface from theedge trimming operation. The edge surface obtained is made up of orpresents or includes fibers of uneven lengths with some of the fiberslaid over. The effect is a rough edge surface on or to which it isdifllcult to obtain an edge coating which is continuous in nature, whichadheres continuously to the edge surface, and which itself presents asmooth surface. The coating obtained is then prone to exhibit loweradherence or adhesion and is more prone to being abraded off than onewhich would be obtained if the coating is initially applied to an evenedge surface. The alternative, and which is an unattractive one, is touse greater amounts of coating material and greater care in theapplication of the same.

In instances where conventional practices provide a clean cut surface asa result of edge trimming, failure to obtain desired adherence betweencoatings and edge surfaces is frequently the result however. This may beattributed to the failure to obtain sufiicient penetration by thecoatings through or beyond the edge surfaces of the bottoms to which thecoatings are applied, when conventional practices are followed.

It is an object of this invention to provide an improved method for edgefinishing shoe outer bottoms which are fibrous in nature.

It is another object of this invention to provide a shoe outer bottom ofa fibrous nature, which exhibits an improved edge finish and edgesurface finish appearance.

Other objects of this invention will come in evidence in the discussionwhich follows.

The objects of this invention may be attained in edge finished shoeouter bottoms which are fibrous in nature by following a multi-step edgefinishing method. The method involves as a first step, (a) introducing aliquid, aqueous sizing into edge portions of shoe outer bottoms, so thatit penetrates beyond the edge surfaces and into portions of the bottomwhich are to remain part of the bottom after edge trimming is carriedout. In the second step (b) trimming of the edges or edge portions iscarried out while the edges are in moist or wet condition to a depthbeyond that where trimming is carried out, due to the presence of thesizing. In the third step (c) with the trimmed edge or edge portions inmoist or wet condition, due to the presence of the sizing in liquidcondition, an edge coating including a moisture-curing polyurethanecomposition is applied in liquid form to the trimmed edge.

The following drawings are included for the purpose of illustrating theinvention in which:

FIG. 1 is a perspective view showing an unattached shoe outsole which isfibrous in nature being subjected to edge finishing;

FIG. 2 is another perspective view showing an unattached shoe outsolewhich is fibrous in nature being subjected to edge finishing;

FIG. 3 is a perspective view with parts broken and in section showing ashoe including outer bottom parts some of which are fibrous in naturebeing subjected to edge finishing; and

FIG. 4 is another perspective view with parts broken and in sectionshowing a shoe including outer bottom parts which are fibrous in naturebeing subjected to edge finishing.

The first step carried out in the practice of this invention, that ofintroducing an aqueous, liquid sizing into the edge surface of a shoeouter bottom, is designed to facilitate both the edge trimming and edgecoating operations which are to follow. In order that improvementsavailable from practice of the invention may be obtained a number offunctions are demanded as a result of carryout this step.

Initially, the application of the sizing should be such that the sizingimpregnates the fibers at the shoe outer bottom edges. In doing sothough, it should penetrate beyond that portion of the fibers, or thosefibers, located at the immediate edge surfaces, and into portions of thefibers, and fibers which are to remain as part of the bottom aftertrimming is carried out. This is for the purpose of improving coatingapplication and penetration conditions. When the bottom is such thattrimming is to be carried out to some depth this may require thatconsiderable penetration be obtained, and, to obtain that more than oneapplication of sizing may be necessary.

The sizing as applied should be capable of swelling the fibers. Inswollen condition, the fibers project outward and cleaner trimming canbe accomplished. Later, on drying the previously swollen fibers retractor constrict to form a more even surface edge which contributes to theobtaining of an improved edge finish and/ or finish appearance.

The sizing should also serve as a lubricant for the trimming operation,particularly where knives or similar cutting objects are to be used fortrimming.

As mentioned above, the sizing should be such that it facilitatespenetration of the edge coating into the fibers. With good penetrationby the coating, secure bonding and/ or coating is facilitated. Further,in this respect the sizing and the coating should be compatible innature. To provide for internal and uniform curing of the edge coatingwhich includes as a major constituent a moisturecuring polyurethane, thesizing is aqueous in nature.

In order that these various functions may be obtained,

the sizing includes a size material having lubricating qualities atleast when it is in moistened condition, which is in an aqueous or watermedium.

Various size materials may be used as the bases for the sizings used inpracticing this invention, These may include starches, caseins, soyprotein, gelatine, animal glue, gums, dextrines, cellulosic esters,rosins, as well as synthetic polymeric materials such as polyvinylalcohol, polyvinyl chloride, polyvinyl esters and others.

A particular group of sizings which are preferred in practice of thisinvention are those which rely on synthetic polymeric materials as sizematerials, the materials being present in a particular form. These arethe synthetic latices which are stable colloidal dispersions ofthermoplastic synthetic polymeric materials which are present as finelydivided, discrete particles in water. They are generally produced byemulsion type polymerizations using methods which are well appreciated.Typical of such latices are those produced from the following monomers.

(a) Styrenes, methyl substituted styrenes, mixtures of the preceding aswell as mixtures including other monomers such as butadiene,acrylonitrile, etc.

(b) Vinyl chloride, vinyl acetate and vinylidene chloride, mixtures ofthe preceding, and mixtures including as other monomers acrylonitrile,butyraldehyde, methylmethacrylate, butadiene, isobutylene, maleic esterssuch as diethyl maleate and dibutyl maleate, etc.

(c) Acrylonitrile, and mixtures of the same with butadiene, isobutylene,vinylidene chloride, chloroprene, maleic esters, etc.

(d) Acrylates such as methyl acrylate, methyl methacrylate, ethylacrylate, butyl acrylate, isobutyl methacrylate, 2-ethyl hexylmethacrylate, mixtures of the preceding, and mixtures including as wellstyrene, acrylonitrile, acrylic acid, butadiene and vinyl acetate.

(e) Butadiene, particularly the 1,3 dienes, mixtures thereof and withstyrene, Z-methyl styrene, ethyl acryiate, vinyl napthaline, etc,

(f) Chloroprene and other halogen-Z-butadienes such as the variouschloroprenes, mixtures of the foregoing as well as with styrene,acrylonitrile, etc.

The aqueous sizings based on synthetic polymeric materials may alsoinclude plasticizers such as dioctyl phthalate, tricresyl phosphate,etc. for the polymeric materials. Various other additive materials mayalso be present such as humectants exemplified by glycerine, sorbitol,etc., as well as lubricants which may be illustrated by waxy partialesters, such as sorbitan and mannitan mno ammonium salts such as stearyldimethyl benzyl ammonium chloride, ethylene oxide condensates of hexitanmonostearates, etc.

The amount of size materials, or solids, which may be present in theliquid, aqueous medium may range on the order of 1% to 10% by weightbased on total weight of the total sizing. Preferred amounts may rangeon the a order of 2% to 5% by weight size material based on the totalsizing.

Application of the sizing to the edges or edge surfaces of the shoeouter bottom may be carried out by any convenient procedure. This wouldinclude spraying, swab bing, brushing or soaking, etc. Application ofthe sizing is generally carried out immediately prior to the finaltrimming step, that is smooth rounding and/or abrading. Except in theextraordinary case, this is sufiicient to insure that the edge surfacepresented at the time of coating will be even, with the fibers presentedthere trim-med evenly and smoothly, and at the same time.

that the edge surface or edge portions will be at least moist due to thepresence of sizing there.

The second step carried out in practiciug this invention is edgetrimming. The step of actual edge trimming is carried out usingexpedients which are known such as rotating knives, etc. In additionhowever, it is prescribed that in practicing the present invention thatedge trimming be carried out while the sizing contained in the fibers orleather is in moist or liquid condition, as manifest by the leather orfibers being in a moist, wet, or damp condition.

The edge coating for use in practice of the present invention is basedon a moisture-curing polyurethane composition. In its initial state,that is adapted for application, it is an isocyanate-containing or-terminated prepolymer which is moisture-curable and capable ofsolvation. Moisture-curable indicates that the prepolymer, and morespecifically the free isocyanate groups contained in the same, have thecapacity .to react with water, either in vapor or liquid state to effectcuring to a flexible, solid state. The moisture required for reactionmaybe provided by the atmosphere or from a separate source of moistureor water.

The isocyanate-terminated prepolymer which may be used may be any ofthose basedon polyols or polyfunctional hydroxyl compounds, andpreferably mixtures of the same. Examples of these include polyethyleneglycol, polybutylene glycols and trimethylol propane. Polyesters whichmay :be used as high molecular weight diols include pentane diol,dihydroxy castor oil derivatives, neopentyl glycol and polypropyleneglycols. Alternate trials may include trimethylol ethane, castor oil,hexane triol and polyoxy propylene adducts of either hexane triol orglycerine.

The polyols are reacted with a polyfunctional isocyanate such as atoluene diisocyanate to obtain an isocyanate terminated prepolymer whichis moisture-curable.

A variation of this procedure involves reacting the polyol with ablocked isocyanate. In this variation the prepolymer is resistant tomoisture-curing at room temperature until such time that the block whichmay be a phenol, thiophenol or the like, is driven off or disposed ofand the isocyanate'reactivityrestored by application of heat.

The prepolymer is dissolved in a solvent such as acetone, methyl ethylketone, methyl isobutyl ketonc, xylene, Cellosolve acetate and the liketo provide a moisture-curable polyurethane based edge coating which iscapable of convenient application to shoe outer bottom edge surfaces.The amount of prepolymer to solvent may range on the order of 30% to 70%by weight with preference ranging 45% to 55% by Weight based on totalweight of coating to be applied.

Various additives may be included in the coating. Examples of theseinclude fiatting agents as well as agents which provide high gloss inthe coating which finally results. An important class of materials whichmay be considered additives are pigments and colorants. It isrecommended that the additives be as moisture-free as possible whenincluded.

The coating is applied in liquid form to a shoe outer bottom edge andbecomes tack-free when the solvent evaporates. The film or coatingdeposited as a result then continues to cure to the desired condition,i.e., continuous etc., by reacting with moisture conveniently obtainedfrom the atmosphere, as well as the moisture retained in the outerbottom as a result of the preceding sizing application.

It bears noting that the reaction of the isocyanate terminatedprepolymer with water or moisture, produces carbon dioxide whichdiffuses slowly from the coating and into the atmosphere as the coatingcures. The coating applied, or rather coating which may also bedescribed as a film or film-coating, developed on deposition from thesolvent should be thin enough for the carbon dioxide to escape.Bubble-free finish coatings, or finish coatings exhibiting a smoothouter surface, generally may be cast up to 20 mils in thickness.

The moisture-curable coating may be applied to the edge surfaces in anyconvenient manner, such as spraying, brushing, rolling, doctoring, etc.It is applied to the trimmed edge surfaces while the latter are in moistcondition, the same being caused by the presence of sizing, and, ininstances to be described later, the presence of an intermediate colorcoating. There may be instances where the amount of moisture present inor on the trimmed edge may be considered too great to facilitateobtaining best results in the urethane coating and in those instancesdrying of an incomplete nature, forced or otherwise may be carried outat the edge prior to application of the prepolymer solution. Drying andcuring of the coating can be forced if desired but in such a case careshould be taken so that the rate of drying or curing will not adverselyaffect the appearance and physical properties which bear on obtaining acontinuous coating having good adhesion with the edge to which it isapplied.

As indicated previously, it may be the more convenient practice inparticular instances to include or apply an intermediate color coating.This is applied after trimming and prior to applying the moisture-curingpolyurethane type coating to the trimmed shoe outer bottom edge. Onereason for this expedient would be to avoid the difiiculty, previouslynoted, which may be met in introducing pigments or colorants into thepolyurethane prepolymer. The intermediate coating may be considered anextension of the sizing, and for that matter the sizing itself, as previously described may include pigments and colorants. To return however,the intermediate coating may differ from the sizing, as previouslydescribed, in that it may contain a higher concentration of solids, forinstance on the order of 35 to 55 weight percent and preferably 40 to 45weight percent each determined on the total weight of the coating.Neither is there reason to require of the intermediate coating that ithave the capacity, nor include agents contributing to it the capacity toprovide lubrication and similarly facilitate the trimming operation.Otherwise, the intermediate coating should be aqueous in nature and itmay be and preferably is based on synthetic latices of the typedescribed for use in the sizings.

Application of the intermediate coatings to the trimmed edges may be byconvenient means including spraying, brushing, rolling, doctoring, etc.Incomplete drying, as previously described, may be carried out on thiscoating prior to application of the moisture-curing polyurethane finishcoating.

Reference will now be made to the drawings wherein various embodimentsof the invention are shown and will be described.

The embodiment of the invention shown in FIG. 1 is directed to edgefinishing an unattached outsole 10 which is fibrous in nature,specifically leather. As shown there, the outsole 10, defined in outlineby edge 12 is in a contoured condition of such nature as to indicatethat it has been previously subjected to a shaping and cuttingoperation, such as dinking-out using equipment not shown. The conditionof edge surface 12a as a result of the preceding shaping is shown in theheel area 16 where a multiplicity of fibers 18 project out to unevenlengths.

Using positioning expedients, not shown, the outsole 10 is directedthrough a progression of edge finishing operations. In the first ofthese, the rough edge surface 12a is advanced through a spray 20 ofaqueous sizing in liquid condition, directed under pressure from a spraynozzle 22. This serves to provide a wet edge surface portion 12b. Thesizing penetrates into fibers 18 and into the fibrous outsole 10 to apoint or depth beyond that to which trimming is to take place. Thedesired wetting penetration is indicated in exaggerated fashion by thedarkened area 24 on the top surface 26 of the outsole 10. Whilemaintaining this wet condition, or to state it differently, while sizing20 is maintained in liquid condition, the edge surface portion 12b isdirected against a fine cutting or trimming wheel 28, rotationallydriven by a spindle 30, the latter being connected to a power source,not shown. The result obtained is a smooth edge surface portion 120,which is wet by sizing or contains sizing in liquid condition. Thewetted edge surface portion 120 is then advanced through a spray 32 ofliquid coating which includes a moisture-curable polyurethanecomposition, the same being directed under pressure from a spray nozzle34. This results in a surface portion 12d which includes a coating ofmoisture-curable polyurethane that hardens on drying and curing to acontinuous smooth outer, finish surface and appearance.

A second embodiment of the invention is shown in FIG. 2. Again anunattached sole 40 is directed through a series of edge finishingoperations. In this embodiment an abrading operation is included. Aspray 42 of sizing is directed onto an edge surface 44 from which amultiplicity of fibers 45 project. Specifically spraying is carried outat edge surface portion 44a, from a spray nozzle 46 to produce weltededge surface portion 44b. The extent of penetration of sizing into theoutsole 40 is indicated by the darkened area 47 on the top surface 48 ofoutsole 40. Then, fine cutting or trimming is performed by a cutter head50 rotated by a spindle 52 to produce the edge surface portion 440.While the sizing is still present in liquid form, the edge surface 44,more specifically, surface portion 440, is advanced against an abradingWheel 56 rotated by a spindle 58. The result is a smooth edge surfaceportion 44d which is then advanced through a spray 60 ofmoisture-curable polyurethane composition in liquid solvated formdirected from a spray nozzle 62. The spray 60 penetrates the surfaceportion 44d and sets up on drying and curing to a continuous coatinghaving a smooth outer finish surface as indicated at edge surfaceportion 44a.

The embodiment of the invention shown in FIG. 3 illustrates the presentinvention being practiced on an assembled shoe stationed on a last 72.The shoe 70 includes an upper 74 assembled with a shoe outer bottom 76including a welt 78, an outsole 80 both of which are fibrous in nature,as indicated by fibers 81, a heel 82 and block 83. As shown, the outsole80 is in rough-rounded condition, the same previously performed, seescallop cuts 84 outlining outsole surface portion 80:: indicating this.The welt 78 is shown in the same condition as indicated by the presenceof scalloping 86 at welt portion 78a. Welt portion 78a and outsole edgesurface portion 80a are advanced through a spray 88 of aqueous sizing inliquid condition, directed from a spray nozzle 90. The spray 88 wets andpenetrates to provide wetted surface portions 78b and 80b. These surfaceportions are then advanced into contact with a cutting wheel 92 which isrotated on a spindle 94. The result is wetted, smooth surface portions78c and 800. The latter are then advanced through a spray 96 ofmoisture-curable polyurethane in liquid, solvated condition directedfrom a spray nozzle 98. The results obtained on drying andmoisture-curing or set up are strongly adherent, continuous finishcoated portions 78d and 80d each of which presents a smooth outersurface appearance.

The embodiment of the invention shown in FIG. 4 also illustrates thepresent invention in connection with an assembled shoe 100. Shoe 100 isstationed on a last 102. A shoe upper 104 is combined with a shoe outerbottom 106, the latter including a welt 108, an outsole 110, a heel 112and heel block 113 all of which are fibrous in nature as indicated bypresence of fibers 114, and with the first two in rough roundedcondition. This is indicated at portions 108a, 110a, 112a and 113a. Thefirst treatment involves applying a spray 115 of liquid sizing fromspray nozzle 116 to obtain wetted surface portions 108b, 110b, 1121: and113b. These surface portions are then advanced against a cutting wheel118 rotated on a spindle 120. The result is wetted, smooth edge surfaceportions as indicated at 1080 and 110s. In this condition the surfaceportions are advanced through a spray 122 of intermediate color coatingmaterial in liquid condition, directed from spray nozzle 124. The colorcoating material is based on an aqueous latex of a thermoplasticsynthetic polymeric material. The result then obtained is anintermediate color coated edge surface portion 108d and 110d which maythen be partially or incompletely dried as desired. The intermediatecolor coated surface portions 103d and 110d are then advanced through aspray 126 of finish coating material which includes a moisture-curablepolyurethane composition in liquid, solvated form. Spray 126 emergesfrom a spray nozzle 128 to develop as coated surface portions Se and1102. With drying and curing a strongly adherent, continuous, finishcoated edge surface portion again referred to as 108a and 1102 areobtained, each presenting a smooth, outer surface and surfaceappearance.

The following example is provided for the purpose of furtherillustrating the invention. When parts are mentioned, unless otherwisedefined, parts by weight are intended.

Example A synthetic latex is prepared by copolymerizing 390 ml. of ethylacrylate and 50 ml. of acrylonitrile in a polymerizing medium whichincludes 550 ml. of water, 15.2 ml. of a fatty alcohol triethanolaminesulfate, 0.7 ml. of an alkyl phenyl polyethylene glycol ether and 28 ml.(1.0% solution) of ammonium sulfate solution. The 40 percent solidsacrylic latex which is obtained is then formulated as (A) a Sizing and(B) an Intermediate Color Coating.

(A) Sizing: The latex obtained above is diluted with water to 4% solids.

(B) Intermediate Color Coating: The latex obtained above is adapted toinclude 0.2% by weight of pigment grade Carbon Black (Benney and SmithMicron X).

A moisture-curing polyurethane prepolymer is produced by reacting 1.0mol. polypropylene glycol, 1.0 mol. 1,3-butane diol, 2.0 mol. oftrimethylol propane and 8.0 mol. of 80-20 mixture of 2,4-toluenediisocyanate and 2,6-toluene diisocyanate. A portion of themoisture-curing polyurethane obtained is mixed under anhydrousconditions with 0.4% by weight of the carbon black. This is thendissolved in a 50:50 mixture of xylene and Cellosolve acetate to give a50% by weight solution. For convenience this solution is referred to as(C) Pigmented Final Coating. Another portion of the moisture-curingpolyurethane, but without the pigment, is similarly solvated. Forconvenience this solution is referred to as (D) Clear Final Coating.

A number of shoe assemblies including attached, previously rough roundedleather outsoles are sprayed at the outsole edges with (A) Sizing. Thesizing penetrates to a distance of about 0.20 inch. The outsoles arethen smooth rounded to remove about 0.15 inch off the edge. The shoesare immediately divided into two groups and the following procedurecarried out within 5.0 minutes.

The first group (I) of shoes are subjected to spraying by the (B)Intermediate Color Coating,followed by an incomplete drying under anair. blast at a temperature of about 700F., followed by a sprayapplication of the (D) Clear Finish Coat. After drying, it is noted thatthe polyurethane coatings are about 0.0006 inch in thickness, arecontinuous in nature, and have smooth outer finish appearances.

The second group (II) of shoes are sprayed directly with the (C)Pigmented Final Coating. After drying the polyurethane film coatingsobtained are noted to be 0.0013

inch in thickness, are continuous in nature and exhibit smooth outerfinish appearances.

The shoes of groups (I) and (II) are subjected to wearing and abrasiontests. Their performances are compared with shoes whose outsoles haveconventional edge finishes, i.e., wax-pigment finishes. The performanceof finishes on the outsoles of the shoes from both groups (I) and (II)show far superior properties of resistance to cracking, peeling,abrasion to those having conventional finishes. In addition the finisheson the outsoles of the shoes of both groups (I) and .(II) arenon-marking. Further than that the finishes obtained on the outsoles ofgroups (I) and (II) shoes do not deteriorate when exposed totemperatures above 350 F. and below 35 F. for extended periods of time(on the order of 60 days).

It will thus be seen that the objects set forth above,-.

among those made apparent from the preceding description, areefiiciently attained, and since certain changes may be carried out inthe above edge finishing method and in shoe outer bottoms obtained frompractice of that method, without departing tion, it is intended that allmatter contained in the above description and shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

Having thus described my invention, what I claim as new and desire tosecure States is:

1. A method for edge finishing shoe outer bottoms which are fibrous innature, the method comprising the steps of (a) providing edge portionsof .the shoe outer bottom in at least moist condition by introducing an;aqueous, liquid sizing into edge. portions of the shoe outer bottom, thesizing penetrating beyond edge portions which.

remain as part of said bottom after edge. trimming is carried out, and,while the edge portions are in at least moist condition (b) trimming theedge portions of the shoe outer bottom and (c) applying a liquid coatingincluding a moisture-curing polyurethane composition to the trimmed edgesurfaces, the said coating being compatible with the sizing.

2. A method for edge finishing shoe outer bottoms according to claim 1wherein the sizing is an aqueous dispersion of thermoplastic syntheticpolymeric material.

3. A method for edge finishing shoe outer bottoms according .to claim 2wherein the thermoplastic synthetic polymeric material is based .on anacrylic latex.

4. A method for edge finishing shoe outer bottoms which are fibrous innature, the method comprising the steps of (a) providing edge portionsof a shoe outer bottom in atleast moist condition by introducing anaqueous liquid sizing into the edge portions of the shoe outer bottom,the sizing penetrating beyond the edge .portions which remain as part ofsaid bottom after edge trimming are waterproof and I from the scope ofthe invenby Letters Patent of the United is carried out and while theedge portions of the shoe outer bottom are in at least moist condition(b) trimming said edge portions of the shoe outer bottom (c) applying anaqueous, liquid intermediate coating and a liquid finish coatingincluding a moisture-curing polyurethane composition to the trimmed edgesurfaces, the said coatings being compatible with each other and thesizing.

5. A method for edge finishing shoe outer bottoms according to claim 4wherein the sizing is an aqueous dispersion of thermoplastic syntheticpolymeric material.

6. A method for edge finishing shoe outer bottoms according to claim 4wherein the intermediate coating is an aqueous dispersion ofthermoplastic synthetic polymeric material.

7. A shoe having an outer bottom which is fibrous in nature with an edgeexhibiting an improved finish, the edge including a first coatingpenetrating an edge portion of said bottom and comprising an aqueousliquid sizing in moist condition, a portion of said edge being trimmedaway and leaving a portion of said edge including said liquid sizingsubsequent to trimming and a second coating comprising a moisture-curingpolyurethane compatible with the sizing.

8. A shoe outer bottom which is fibrous in nature with an edgeexhibiting an improved finish, the edge including a first coatingpenetrating an edge portion of said bottom and comprising an aqueousliquid sizing in moist condition, a portion of said edge being trimmedaway and leaving a portion of said edge including said liquid sizingsubsequent to trimming and a second coating comprising a moisture-curingpolyurethane compatible with the sizing.

9. A shoe having an outer bottom which is fibrous in nature with theedge exhibiting an improved finish, the edge including a first coatingpenetrating an edge portion of said bottom and comprising an aqueousliquid sizing in moist condition, a portion of said edge being trimmedaway and leaving a portion of said edge including said liquid sizingsubsequent to trimming, an intermediate coating comprising coloringmaterial in aqueous liquid and an edge coating comprising amoisture-curing polyurethane, the said coatings being compatible witheach other.

10. A shoe outer bottom which is fibrous in nature with an edgeexhibiting an improved finish, the edge including a first coatingpenetrating an edge portion of said bottom and comprising an aqueousliquid sizing in moist condition, a portion of said edge being trimmedaway and leaving a portion of said edge including said liquid sizingsubsequent to trimming, an intermediate coating comprising coloringmaterial in aqueous liquid and an edge coating comprising amoisture-curing polyurethane, the said coatings being compatible witheach other.

References Cited UNITED STATES PATENTS 1,961,318 6/1934 White 121422,051,374 8/1934 Frost 12-142 2,058,454 10/1936 Hopkins l2-146 X2,852,413 9/1958 Tischbein 117139 X 2,884,336 4/1959 Loshaek et a1.11711 JORDAN FRANKLIN, Primary Examiner. H. H. HUNTER, AssistantExaminer.

7. A SHOE HAVING AN OUTER BOTTOM WHICH IS FIBROUS IN NATURE WITH AN EDGEEXHIBITING AN IMPROVED FINISH, THE EDGE INCLUDING A FIRST COATINGPENETRATING AN EDGE PORTION OF SAID BOTTOM AND COMPRISING AN AQUEOUSLIQUID SIZING IN MOIST CONDITION, A PORTION OF SAID EDGE BEING TRIMMEDAWAY AND LEAVING A PORTION OF SAID EDGE INCLUDING SAID LIQUID SIZINGSUBSEQUENT TO TRIMMING AND A SECOND COATING COMPRISING A MOISTURE-CURINGPOLYURETHANE COMPATIBLE WITH THE SIZING.